1. Field of the Invention
This invention relates to an extraction cleaning machine and, more particularly, to an upright extraction cleaning machine.
2. Description of Related Art
Upright extraction cleaning machines have been used for removing dirt from surfaces such as carpeting, upholstery, drapes and the like. The known extraction cleaning machines can be in the form of a canister-type unit as disclosed in U.S. Pat. No. 5,237,720 to Blase et al. or an upright unit as disclosed in U.S. Pat. No. 5,500,977 to McAllise et al. and U.S. Pat. No. 4,559,665 to Fitzwater.
Current upright extraction cleaning machines can be made easier to use by limiting the weight and number of components, such as fluid storage tanks, on the pivoting handle of the upright cleaning machine. Reducing the weight that a user must support as the handle is tilted rearwardly can also lower the center of gravity for the machine, which results in a better feel to the user.
Furthermore, the current extraction cleaning machines can be made easier to use and better adapted for a variety of cleaning conditions. For example, none of the current extraction cleaning machines includes an elevator responsive-to-handle position for restraining a floating roller-type agitation brush, which is automatically height adjustable in response to changes on the surface being cleaned. Another problem inherent with the known extraction cleaning machines is the difficulty of filling and emptying the fluid supply chamber and fluid recovery chamber, particularly with bladder-within-a-tank type assemblies. Further, none of the current upright extraction cleaning machines are simply convertible to a pre-spray applicator for directing cleaning solution to and agitating the surface to be cleaned without applying suction. Finally, current extraction cleaning machines do not use a the same motor to drive an agitation brush as well as an impeller. Is some cases a separate motor is used. In other cases, a turbine is used to drive the agitation brush or brushes which diminishes the suction power available to extract the dirty solution from the floor surface.
A more recent development in the extraction cleaning industry is the use of steam or hot water as a cleaning agent. The cleaning machine incorporates a boiler or other means for generating steam or hot water, which is pumped to an applicator where it is brought into contact with the surface being cleaned. Because the steam is airborne, it may be unsafe to include detergents and the like in the cleaning solution. Further, while the steam systems have the advantage of creating a temperature that effectively kills a wider range of microbes, bacteria, microorganisms, and mites, the steam systems generally suffer from poor cleaning performance. Additionally, the high power requirement for generating steam may not be sufficient with ordinary 120V power supplies for running a vacuum motor as well as the steam generator, so cleaning performance is further hindered. Also, by adding a heater to a fluid supply chamber, the user may be inconvenienced by the amount of time required to heat the contents of the supply chamber to the desired temperature. Conversely, conventional detergent cleaning systems are somewhat effective at cleaning surfaces, but could be made more effective by raising the temperature of the cleaning solution to some temperature below the boiling point. There is an optimal temperature at which cleaning performance is maximized without causing damage to carpets or, setting stains. This temperature is around 150xc2x0 Fahrenheit.
According to the invention, a portable surface cleaning apparatus comprises a housing adapted for movement along a surface to be cleaned, a liquid dispensing system and a liquid recovery system. The liquid dispensing system includes a liquid dispenser mounted to the housing for applying liquid to a surface to be cleaned, a liquid supply tank for holding a supply of cleaning liquid and a liquid supply conduit fluidly connected to the liquid supply tank and to the dispenser for supplying liquid to the dispenser. The liquid recovery system comprises a recovery tank removably mounted on the housing and having a liquid recovery chamber for holding recovered liquid, a suction nozzle associated with the housing adapted to draw dirty liquid from the surface to be cleaned, a working air conduit extending between the recovery chamber and the suction nozzle and a vacuum source in fluid communication with the recovery chamber for generating a flow of working air from the nozzle through the working air conduit and through the recovery chamber to thereby draw dirty liquid from the surface to be cleaned through the nozzle and working air conduit and into the recovery chamber to thereby recover dirty liquid from the surface to be cleaned.
In accordance with one embodiment of the invention, an accessory hose is mounted at one end to the housing for option above floor cleaning; a unitary duct is connected at a first end to the accessory hose one end and at another end, is connected to the working air conduit at an accessory hose inlet; and a conversion valve is mounted in the working air conduit between the suction nozzle and the accessory hose inlet to selectively connect the vacuum source to either the suction nozzle or to the accessory hose.
In one embodiment, portions of the unitary duct are flat. In a preferred embodiment of the invention, at least one of upper and lower portions of the unitary duct is flat. Further, an intermediate portion of the unitary duct extends beneath the recovery tank.
In another embodiment, the housing includes a base housing and an upright handle, and the upright handle is pivotally mounted to the base housing. Further, the recovery tank is removably mounted in the base housing. In addition, the accessory hose is mounted at the one end to a rear portion of the base horsing.
In accordance with one embodiment of the invention, a fluid passageway is provided between the fluid supply chamber and the recovery chamber of the tank, whereby the tank is in fluid communication with the fluid supply chamber and the pressure in the flexible bladder is equalized with the pressure in the tank as the cleaning fluid is dispensed and the dirty liquid is collected in the tank. The flexible bladder preferably includes an outlet opening in the bottom portion thereof connected to the fluid supply conduit. In one embodiment, the flexible bladder extends between a bottom surface of the tank and an upper portion of the tank.
In a preferred embodiment, the fluid passageway between the fluid supply chamber and the recovery chamber of the tank comprises a filling spout disposed in an upper portion of the flexible bladder. A baffle plate is mounted within the upper portion of the tank and includes an opening. The filling spout on the flexible bladder extends through the opening in the baffle plate and is supported thereby. Preferably, the tank includes a removable lid on a top portion thereof and a filling spout is disposed between the baffle plate and the lid.
Further according to the invention, in one embodiment, the tank has an outlet opening in a bottom portion thereof and a drain plug is removably mounted in the outlet opening.
In another embodiment, a lid mounted on the tank defines an expansion chamber having an inlet opening and an outlet passage between the expansion chamber and the tank. The working air conduit is connected to the lid inlet opening so that the working air is drawn through the expansion chamber in the lid and into the tank. A first diverter baffle in the expansion chamber reverses the direction of flow of the working air between the inlet opening and the outlet passage. A second diverter baffle in the outlet passage reverses the direction of flow of the working air between the expansion chamber and the tank. Thus, the working air flow reverses direction twice between the inlet opening of the expansion chamber and the tank. The lid is preferably removably mounted to the tank. In one embodiment, the outlet passage extends beneath the expansion chamber and includes an outlet opening and the filling spout in the flexible bladder includes an opening beneath the lid and substantially above the outlet opening in the outlet passage. Further, the filling spout is disposed between the baffle plate and the lid and the lid includes a shroud extending downwardly from the bottom surface thereof surrounding the filling spout to a point below the opening of the filling spout. Preferably, the shroud extends beneath the outlet opening of the outlet passage.
In another embodiment, the working air conduit includes a conversion valve for selectively opening and closing fluid communication between the tank and the suction nozzle. A manual actuator knob is connected to the conversion valve for movement between first and second positions and thereby selectively moving the conversion valve between open and closed positions. According to the invention, an over-center linkage mechanism is connected to the manual actual knob to bias the conversion valve to the open and closed positions. In a preferred embodiment, the over-center linkage mechanism comprises a spring-biased plunger assembly mounted to the actuator knob for movement therewith. The actuator knob is preferably mounted to the base module for rotational movement between the first and second positions and the spring-biased plunger assembly is mounted to the actuator knob for rotational movement therewith. In a preferred embodiment, the conversion valve is pivotably mounted to the base for rotational movement between the open and closed positions and the conversion valve includes an arm having a distal end extending to the plunger assembly and rotatably connected thereto. The rotational motion of the actuator knob is translated to rotational movement of the conversion valve through the arm.
In yet another embodiment, a flow indicator is mounted to the base module and has a visibility window observable to a user and the flow indicator is disposed in the fluid supply conduit and is responsive to the flow of fluid through the fluid supply conduit to visually indicate the flow of fluid through the supply conduit to the user. In a preferred embodiment, the flow indicator comprises an impeller rotatably mounted in a flow indicator housing and driven by the fluid flowing through the flow indicator.
In still another embodiment of the invention, a fluid supply conduit in the liquid dispensing system includes a pump fluidly connected to the fluid supply chamber and to the dispensing nozzle for supplying cleaning fluid to the dispensing nozzle. A pump primer is connected to the pump for priming the pump and includes a valved opening connected to the vacuum source. According to the invention, the pump primer includes a housing defining a priming chamber with an inlet opening connected to the fluid supply chamber and an outlet opening connected to an inlet for the pump. In a preferred embodiment of the invention, the valved opening is in an upper portion of the priming chamber. Further, the pump primer includes a valve chamber and a plunger chamber. The valve chamber has an inlet opening defined by the valved opening in the primer chamber and an outlet opening defining an inlet opening to the plunger chamber. The plunger chamber has an outlet opening in fluid communication with the vacuum source. A buoyant plunger is reciprocally mounted in the plunger chamber for generally vertical movement therein. A valve is mounted in the valve chamber and reciprocally movable between the inlet opening and the outlet opening thereof and connected to the plunger for movement therewith. By this structure, the valve closes the outlet opening to the valve chamber when fluid in the plunger chamber raises the plunger and the valve closes the inlet opening when fluid in the plunger chamber falls to a predetermined level. In a preferred embodiment of the invention, the valve in the valve chamber is an umbrella valve.
In a further embodiment of the invention, the surface cleaning apparatus includes a fluid supply conduit including a pump fluidly connected to the fluid supply chamber and to the dispensing nozzle for supplying cleaning fluid to the dispensing nozzle. The pump has a drive shaft for driving the pump. An agitation brush is mounted in the forward portion of the base module. A motor is mounted in the base housing and has a motor drive shaft connected to the agitation brush for rotatably driving the agitation brush. According to the invention, a first mechanical connector extends between the motor drive shaft and the pump drive shaft, whereby the motor drives both the agitation brush and the pump. In a preferred embodiment of the invention, the motor drive shaft is connected to the agitation brush through a second mechanical connector between the pump drive shaft and the agitation brush. The pump drive shaft has a mechanical step-down device connecting the drive shaft to the first mechanical connector to step down the speed of rotation of the motor shaft in the pump drive shaft. Preferably, the first and second mechanical connectors are belts, with the second connector preferably being a timing belt and the first connector preferably being a stretch belt. Typically, the stretch belt rides directly on the motor drive shaft. In a preferred embodiment of the invention, inner and outer pulleys are mounted in axially spaced relationship on the pump shaft, wherein the timing belt is reeved around the outer pulley and the stretch belt is reeved around the inner pulley. Further, there is a baffle between the inner and outer pulleys to minimize liquid transfer between the inner and outer pulleys. The inner and outer pulleys are preferably of a size to step down the speed of rotation of the motor shaft at the pump drive shaft and at the agitation brush. Further according to the invention, the base module includes a housing with an opening adjacent to the first mechanical connector and a removable door is selectively mounted to the housing to cover the opening. Preferably, the removable door includes a flange and the housing includes a groove and the flange is slidably received in the groove to at least partially support the door in the opening. The housing preferably includes a second removable door which forms a portion of the baffle between the inner and outer pulleys.
Further according to the invention, the base module includes an upper housing portion and a lower housing portion and an upright handle is pivotably mounted to the rear portion of the base module through at least one bearing for rotatable reception in the housing. According to the invention, a socket is formed between the upper and lower housing portions for rotatably receiving the bearing. Preferably, the bearing is formed integral with the lower portion of the upright handle. Desirably, the socket is formed by arcuate surfaces in mated edges of the upper and lower housing portions. The lower portion of the upright handle includes diverging arms, each including a bearing. Each bearing is formed integral with the lower portion of the upright handle. Typically, wheels are mounted to an axle which are received within the bearings for rotationally mounting the wheels to the handle.
In accordance with another embodiment of the invention, a portable surface cleaning apparatus has a base module with a brush assembly having an agitation brush generally disposed in the front portion of the base module and a pivot arm for pivotably supporting the agitation brush relative to the base module. A first end of the pivot arm is mounted to the agitation brush for rotation of the agitation brush with respect to the pivot arm and a second end of the pivot arm is pivotably mounted to the base module, whereby the brush assembly is free-floating to adjust to different surface heights. According to the invention, an elevator assembly is reciprocally mounted to the base module and movable in response to movement of the upright handle from an operative position to the upright position. The elevator assembly includes an arm disposed at one end adjacent the pivot arm and having a lifting surface for upwardly pivoting the pivot arm and a second end extending toward the handle and having a contacting surface for sliding along the outer surface of the lower portion of the handle. Movement of the arm toward the front portion of the base module by pivoting the upright handle to the storage position is translated into movement of the agitation brush away from the surface to be cleaned. Preferably, a spring biases the arm toward the handle.